Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) state segment	Dec. 31, 2022 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of states in which entity operates | state	11
Number of community regional banks operating in distinct geographical areas | segment	7
Securities for which entity has right to sell or repledge	$ 877.0	$ 2,300.0
Security resell agreements average amount	1,300.0	2,400.0
Security resell agreements maximum amount, outstanding	$ 2,000.0	$ 2,700.0
Percentage of acquired assets and all assumed liabilities recognized in business combination	100.00%
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Security resell agreements maturity (in days)	30 days
Minimum | Building
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of properties (in years)	25 years
Minimum | Furniture and Equipment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of properties (in years)	3 years
Minimum | Software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of properties (in years)	3 years
Maximum | Building
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of properties (in years)	40 years
Maximum | Furniture and Equipment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of properties (in years)	10 years
Maximum | Software
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Estimated useful lives of properties (in years)	10 years